Recording instrument



March 5, 1940. w. K. MATHVESON ET AL RECORDING INSTRUMENT Filed Dec.

1, 1937 v 2 Sheets-Sheet 1 INVENTORS .K. MATHE ATHUR c. H

i 45 wiLuA-M Patented Mar. 5, 1940 UNITED STATES I PATENT- OFFICE RECORDING INSTRUMENT William K. Matheson, Brooklyn, Y.,

and

16 Claims.

This invention relates to recording instruments.

More particularly, this invention relates to instruments in which a primary element, responsive to variations in external conditions, moves an indicating element which embodies or in turn actuates a stylus, printing device, or other means for inscribing a legible record of such external condition upon a chart or tablet graduated in appropriate units, such legible record being continuous over a predetermined time period.

In this invention, the stylus or equivalent and I its therewith associated primary actuating element are preferably pivotally mounted upon a carriage movable relatively to a fixed chart, the carriage movement, in at least one direction, being at a definitely controlled or timed rate. The stylus, in accordance with common practice, is arranged to respond to the movement of the primary actuating element per se, the stylus movement being preferably substantially at right angles to the direction of carriage movement.

It is a feature of this invention that a reverse movement of the carriage, i. e., a movement in a direction other than that of the timed movement thereof, is effective immediately to raise the stylus clear of the chart, such raised position being maintained until manually operable repositioning means are actuated.

It is yet another feature of this invention that the mounting of the stylus and primary actuating element on a movable carriage permits an appreciable simplification of the timing mechanism, a simple clock-escapement or equivalent means adequately controlling the rate of carriage movement. Any conventional power means for actuating the clock-escapement may be employed; however, a spring-motor drive for such escapement finds particular advantage in mak ing the instrument entirely independent of external power, such as electric power. Addi tionally, the reverse movement of the carriage may be concomitant with the winding of the spring motor, the fully wound status of such spring motor most preferably coinciding with the positioning of the stylus at and above the datum time line of the chart, in which circumstance, operation of the stylus-resetting means is effective to re-position the stylus on the chart, and to position it accurately at or on the datum line. t will thus be obvious that thestylus may be at the datum time line only in the circumstance of a fully wound'spring motor, thus preeluding any possibility of the motor "running down before the desired travel of the pen over the established time period has been completed.

.A further feature of the invention resides in means for automaticallyhalting the clock-escapement movement at a suitable time after the completion of carriage travel, the clock-escape- 5 ment automatically being restored to full operative status upon rewinding the spring of the clock-escapement motor.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Fig. l is a perspective of a recording instrument made pursuant to the present invention;

Fig. 2 is a plan View, partly in section, taken through the points 2-4 of Fig. 1, the position r f the indicator and stylus being changed to indicate substantial expiration of the time period of the record;

Fig. 3 is an elevation of the carriage and its therewith associated primary element;

Fig. 4 is an elevation, taken through 4-4 of Fig. 2;

Fig. 5 is a sectional elevation of the primary element, taken through 5-5 of Fig. 2, detailing its mounting in the carriage;

Fig. 6 is a plan section of the carriage, taken through 6-6 of Fig. 3, the position of the cam and cam pin being slightly altered with respect to Fig. 3, for clarity;

Fig. 7 is an elevation, partly in section, illustrating the position of carriage and stylus on the completion of wind of the spring motor of the escapement means;

Fig. 8 is a plan section taken through 88 of Fig. '7, the position of the carriage being in this figure at the extreme upper limit of travel; Fig. 8 further indicates the operation of the escapement--stopping means;

Fig. 9 is a vertical section of the escapement mechanism. and associated structure, taken through. 99 of Fig. 8;

Fig. 10 is abottom view, showing the manual carriage-adjustment lever;

Fig. 11 is an exploded perspective of the manual carriage-adjustment organization; and

Fig. 12 is a perspective of the slidable carriage and its associated cam means.

A recording instrument ill, see Figs. 1 and 2, includes a primary element ll sensitive or responsive to external conditions, an indicator l2 associated with said primary element and arranged to be moved or otherwise actuated thereby, a stylus l3 or equivalent marking or printing device, preferably unitarily combined with said indicator and arranged to inscribe a legible record on a suitably delineated chart or tablet M, and means providing for such in scrip-tion or record to continue over an estab lished time period, such means including a timing mechanism 15, a carriage 16 arranged to support said primary element and said stylus, guide-rods or trackway ll on which carriage 15 may be slidably mounted for travel toward or away from said chart, and means such as the spring motor It for moving the carriage.

By an element sensitive to external conditions as used hereinafter, and in the appended claims, is meant a structure preferably so affected by conditions such as ambient temperature, condition of pressure, electric current, mechanical motion or the like, as to be physically altered in varying degree by the intenstiy or value of such external condition, the physical alteration being most preferably a movement or displacement of such element of suitable magnitude.

its typical of a recording instrument made pu suant to this invention, the primary element l! is illustrated as being a conventional lob-metallic coil, said element tending to uncoil under conditions of rising temperaturesand to coil under ably coextensive with the full travel of the carriage, are in conformity with the function of the instrument a recording thermometer; the cover of a mechanical motion recorder, electrical measuring instrument, or th like, need not be ventilated to such extent.

Cover may be provided with an opening 23, rende ing the chart M visible behind a suitable transparent protective window.

-Carriage guide rods l l may be supported in parallelism, and in suitable spaced relationship to base fill, on a suitable rear angle member and a front wall iii of a casing 27 arranged to house the timing mechanism l5 and its associated structure. Projecting tips 28 at the terminal ends of rods H may snugly engage suitable holes in the supporting members 25, 2b to position the rods ll. A table or chart plate 30 suitably supports the chart M. crews 3i serve to hold casing 2'? removably on base 23.

Chart it may be positionedon the chart plate by suitable side plates and end lugs 33; longitudinal spring members secured to side plates serve to press the chart I l yieldably against the chart plate. The chart may thus he slid forwardly beneath springs until the forward edge of the chart abuts against the lugs The inner end of primary element H may be secured to a spindle 35 supported for free axial rotation in a yoke formed by a superstructure member 35 of carriage l6 and an upper bridge member 3?, member 31 being suitably secured by means of posts and nuts ill. The outer end of the primary element is suitably anchored. The primary element is preferably of such organization of dissimilar metals that a reduction in temperature causes a coiling of the primary element and corresponding clockwise rotation. of the spindle 3-5, whereas a condition of increasing temperature urges the spindle into counter-clockwise rotation. The upper end 35a of spindle 35 receives a collar ll to which the indicator 12 fixedly secured. The response of element H to temperature variations-4. e., its response to external ccnditions-therefore causes the indicator and its associated stylus 13 to swing apu'opriately across the chart M. Preferably the indicator is counter-weighted as by a weight 42 of suitable magnitude.

Cal ration of primary element H may be efiected by a displacement of its bifurcated anchor member to the right or left, as viewed in "'3: 2, such movement enforcing a rotation of spindle in desired degree. The necessary movement of member d3 may be accomplished by an adjustment mechanism including an adjustment screw 35, see Fig. 12, passing through a suitable opening in a vertical ear 49 of an angle-shaped slide member 61 and into a femalethreaded hole in a post 45, the latter being fixedly supported on member by a neck-portion 52,

which additionally functions as a fastenin rivet. The neck 52 suitably positions the .l of post 3-6 above the member 36, and pro- 3 for slidably confining the base portion of is member ll between the member and the head of post it, the neck 52 passing through a suitable slot 5! in the base of member 21. The eth of slot 5! therefore establishes the amount or movement of the slide member 41. On screwin the adjustment screw inwardly, the head thereof, bearing against ear 49, drives the slide to the left, against the resistance of a spring interposed between the ear and the post 66. 21 unscrewing the adjustment screw, the expansion of spring 48 urges the member M to right. A pin 5%, secured to an end of mem- 5,1 and passing through the bifurcated portion of anchor member 43 operatively associates the primary element H with the adjustment mechanism, td effect desired rotation of the spindle 35.

Carriage 56, see Fig. 12, further includes a base at suitably mounted on guideways IT so as to be fr ly slidable thereon. Advantageously, base may have a downwardly depending flange 55, 6, at the rear thereof, and a similar at its forward portion. Holes suitable :assage of rods l1 therethrough are provided in these flanges, the single hole in flange 56 being alignment with one of the two holes in flange lit The second of 57, Fig. 6, may suitable of rod the two holes in flange 55, elongated to provide for l! therethrough and thus insure the free travel of the base 54 on the rods ll. 13 base 554 is supported on the rods ii at three points of mount. The base 54 :hrrther includes downwardly extending side 58, said side plates forming members on which the superstructure 36 may be pivotally mounted, side plates 59 of the latter suitably overlying plates 58. The transverse pintle 6i: provides for such pivotal support.

In this invention, the timed travel of stylus i3 is accomplished by moving the stylus I3 over a fixed chart M, the time datum line Me of the chart being at the bottom thereof, see Fig. 2.

Full travel of stylus may be as desired, that of the illustrated embodiment being effected in twenty-four hours.

To accomplish the timed travel of the stylus it, means are provided whereby the entire car-- .r in

Iii)

all) or timed rate.

riage l6, supporting the primary element, indicater, stylus, and associated elements, moves away from the chart M at a definitely controlled The motive power for the carriage may advantageously be the tensile spring [8; the rate of movement may be governed by the timing mechanism l5, which opposes the pull of the spring means 18.

Timer l5, as illustrated, may be spring-motor driven, such type of motor making the escapement entirely independent of external power source. The spring-motor 62 may have a drum 63, see Fig. '7, on its shaft 6 I, on which drum may be wound and suitably secured a portion of a cable 65. The cable may be carried around an idler spool 66, pass through a suitable opening 6! (see Fig. 8) in front wall 26 of housing 21, extend parallel to guide rods l1, thence around a sheave 68 rotatably secured to base 20, and finally attach to the spring I8, the latter preferably being anchored, as by a pin Hi, to the base 20.

It is preferred to secure carriage IE to the stated cable in a manner providing for ready adjustment and/0r removal of the carriage. Ac cordingly, a plate I! and screw 12 may be arranged to clamp the cable tightly against one of the side plates 58 of carriage sub-structure M.

The spring-motor B2, driving or rotating in a direction counter-clockwise of Fig. 2, may be governed in its rate of rotation by conventional escapement means 15. Such rotation of springmotor 62 and its therewith associated cable-drum. 65 permits an unwinding of the cable and concomitant rearward travel thereof under the pull of the spring !8. The carriage structure It, being clamped to cable 65 is thus drawn rearwardly away from the chart M. In other words, the pull of spring 18 on the cable $5 is opposed and controlled by the timed unwinding of the cable 65 on its drum 63.

. Advantageously, the length of the cable is of such dimension that at the completion of the maximum carriage travel, such maximum being established by the rear angle member 25, a quantity of cable equivalent to several hours of additional spring-motor movement remains wound on the drum. 63. Means are provided, as later described, for stopping the action of the spring motor prior to the complete unwinding or re lease of the cable. The drum. 63 is preferably of such diameter and surface area that the cable, when wound thereon to full required extent, is arranged in a single layer, thus insuring an even paying off of such cable for each rotation of the drum 63.

It is a feature of the invention that the superstructure 35 of the carriage l6 may be inclined or canted with respect to the carriage, such move ment affording means for lifting the stylus l3 clear of the chart in the circumstance of removing or replacing the chart, and/ or in the circumstance of bringing the stylus into register with the datum time line on starting a new record run.

Desirably, such canting of the superstructure may be effected automatically on a suitable reverse movement of the carriage, i. a; movement of the carriage in the direction of the chart, as distinguished from its timed or controlled movement away from the chart.

In this invention, the reverse carriage movement may be accomplished in either one of two ways: by the manual operation of suitable adjustment lever means, as later described, or by winding spring-motor 62, the latter operation causing a rotation of its associated drum 63 clockwise of Fig. 2 with a resultant winding of cable 65 on the drum and movement of carriage 16 in the direction of the chart.

To rock the superstructure 36 rearwardly on its pintle 60, the full extent of such rocking movement being illustrated in Fig. 7, cam means may advantageously be used. Such cam structure may include an L-shaped frame "16, see Fig. 6, having suitable perforations to permit the passage of guide rods I'I therethrough, said frame thereby being slidably mounted on said rods in a manner similar to that of base 54 of carriage It. The frame 16 is preferably frictionally held against free movement along the rods by a leaf spring 1'! suitably secured to a side arm 13 of frame '18 and arranged to bear against one of the rods I? as indicated in Fig. 6.

Further, the cam structure includes a pin 80 fixedly secured to the side arm 18 and projecting at right angles therefrom, as indicated in Fig. 6. As shown in Fig. 3, the superstructure 36 of the carriage is provided with downwardly extending side plate 8!, provided with a suitably sloping cam slot 82, the disposition of side plate 8| and slot bringing the latter into cooperative alignment with the cam pin 80.

As above stated, the cam frame It is held against free movement along the guide rods ll. However, during movement of the carriage It in either of its two permitted directions, one or the other of the ends of the cam slot 82 will engage the pin 86, whereupon on continued movement of the carriage, the cam frame 15 and its associated structure will be drawn in the direction of carriage movement. During the timed movement of the carriage 16, i. e., movement away from the chart M, the forward or higher end of the slot engages the pin 88, see 3; desirably, an operative, i. e., chart inscribing po sition of stylus i3 is attained just prior to the slot-end and pin engagement. It will be thus obvious that during the entire rearward movement of the carriage, the stylus will be in full operative position.

When it is desired to cant the superstructure 36, and thus to raise the stylus clear of the chart, the carriage 56 may be moved in the direction of the chart. The cam frame member 15 being frictionally held against displacement, the car" riage I6 may be moved toward the chart without effecting a similar immediate movement of the stated cam frame. The carriage movement causes the sloping cam slot to bear against stationary pin lid, and accordingly, the effect of the slope of such cam slotis to tilt the superstrum ture 36 into the position shown in Fig. 7. At the completion of the camming movement, the rear or lower end of the slot 122 engages pin 80, and continued movement of the carriage structure in the direction of the chart draws cam. frame H3 in the same direction.

It is a feature of this invention that the organization of carriage It, and the arrangement of drive cable 65 with respect to the drive motor 62 brings the stylus to a position at and above the datum. time line of the chart M coincidentally with the fully wound status of the spring-motor 63. It will be obvious, therefore, that at the start of a record run, the spring-motor is necessarily in fully wound condition.

An adjustment lever 35, see Figs. 10 and 11, may be employed to cant the superstructure 36 when desired to raise the stylus clear of the chart, and finds a further application in bringing the stylus into operative contact with the chart, after the operation of winding the spring-motor. In accordance with the method of canting the superstructure previously set forth, it is necessary to cause a suitable movement of the carriage to effect the resultant desired operation of the cam means thereof. Such movement of the carriage may be accomplished either by winding the spring-motor, as described, or by displacing the idler spool E l, such displacement being under the control of the adjustment lever 85. Referring now to Figure 1.1., in which the adjustment lever organization is illustrated in exploded perspective, and to Fig. 9, a spring washer 93, a follower M, an arm 85, carrying spool 66 rotatably at one end thereof, and a balance-wheel stop 3'! are pivotally mounted, in the order named, on a common shaft 88, said shaft having a rivet head 99 supporting lever 85, and provided with a nut 9| to integrate the assembly.

Particularly, see Fig. 9, lever 85 and spring washer 33 are disposed beneath the base 20, follower rests on the base, and arm 85 is carried directly on follower Fit. The follower is provided with a downwardly projecting tongue 92, which passes through a suitable slot 93, see Figs. 8 and 10 in the base 26, and engages the lever 85 by passage through a suitable hole 94 therein, the diameter of the latter restricting play or backlash of tongue 92 therein to a minimum. Thus, a movement of the lever 85 about the common shaft 88 causes an identical movement of the follower 85. The tongue 92 serves additionally as a means of limiting the travel of lever 85, by contacting one or the other end of the slot 93. The arm 36 has formed at a side thereof a short tongue 95, preferably projecting below the bottom surface of arm ilfi to an extent slightly less than the thickness of the material of follower 84. The tongue 95, by being in the path of movement of follower 8 4 when the latter is moved in direction clockwise of Fig. 8 on suitable manipulation of lever 85, thereby causes the arm 85 to move in that direction. However as appears in Fig. 8, the arm 86 may have such clockwise movement entirely independent of and greater than that of the follower 8 and its therewith associated lever 85. A knob, as 85a, may provide for ready manipulation of the lever 95.

Normally, the pull of spring-motor l8 urges the arm at; into rotation counter-clockwise of Fig. 2, and thus keeps tongue 95 at all times in contact with an edge of follower 84. When the lever 85 is in position which may be substantially at right angles to the line of travel of the carriage, indicated by the dotted line in Fig. 2, the superstructure 36 and its therewith associated primary element, indicator, and stylus, may be in the Fig. 3 position, that is, chart inscribing position. Should it be desired to lift the stylus clear of the chart, as in the circumstance of changing the chart, the lever 85 may be moved clockwise of Fig. 8 to the extent permitted by the slot 93. Such downward movement causes a following movement or rotation of arm 89 and idler 66, and therefore moves the carriage l 5 toward the chart. Immediately, the cam and slot organization of the carriage functions to cant the superstructure and raise the stylus clear of the chart. The friction washer 83 is eifective to hold the lever 95 in any position, against reaction of the spring-motor l8.

Upon manual return of the lever 85 to its normal position, the spring-motor Ill holds the tongue 95 in contact with an edge of follower 84, and thus the arm 36 and its mounted idler 66 move counter-clockwise of Fig. 2 with an accompanying rearward movement of carriage It. By the automatically following operation of pin and cam slot 82, the stylus is returned to operative position on the chart. Desirably, when the stylus is in such operative position, the movement of lever to the full extent permitted by slot 93 has not been utilized, thus providing for additional rearward movement of the carriage for purposes of adjustment of stylus 13 on the chart.

At the termination of the spring-motor winding operation, the stylus 13 will have been brought to a point at and above the datum time line 14a of the chart. The operation of winding the springmotor holds the lever 85 and associated structure against accidental displacement. To bring the stylus [3 into operative contact with the chart, it is necessary to rotate the superstructure downwardly, such superstructure movement necessitating an appropriate movement of the carriage l6. For effecting such movement, lever 85 may be rotated clockwise of Fig. 8, to the limit permitted by slot 93. Such movement of lever 95, as indicated in broken line in Fig. '7, serves to move the entire carriage 96 an additional step in reverse direction, the amount of such step being preferably greater than the projected effective length of the slot 582. Such manipulation of lever 85 therefore moves the stylus, still clear of the chart, beyond the datum time line, as represented in Fig. '7, and also moves the cam frame 16 a similar amount. On the return of lever 85 to its Fig. 10 position, the spring 18 is permitted to draw the carriage rearwardly. The cam base 16 remaining stationary by reason of the frictional contact of spring 7'! with the guide rod 11, the pin 89 and cam slot 92 function to swing the superstructure 35 in a direction counter-clockwise of Fig. 7, and thus the stylus is positioned on the chart, at the datum time line.

Desirably, the spring of spring-motor 62 has an appreciable factor of safety. For example, when the carriage travel has completed its full record run, the carriage at such stage closely approaching the angle member 25, the spring-motor 52 will continue to function for several additional hours, such continuing function of the motor permitting the carriage to reach its extreme limit of travel, as established. by the abutment thereof against angle member 25. To avoid a slackening of the cable 65 on continued rotation of springmotor drum 63 and thus to obviate any possibility of the cable dropping away from the spool 63, means are provided to rotate the arm 88 clockwise of Fig. 8, thus serving to take up slack of the cable 65. Such clockwise rotation may result from the action of a suitable tensile spring 96 anchored to a post 91 on the base 2%) and attached to a suitable ear 93 on the arm 86. The strength of the tensile spring 96 is purposely insufficient to overcome the pull exerted by the spring-motor is. However, when the carriage 15 comes to rest against the angle member 25, the spring I8 is no longer effective, and the tensile spring 96 need only overcome the frictional resistance of arm 86. Desirably, such movement of the arm 86 may be utilized to cause the spring-motor to stop, by stopping the escapement balance-wheel 75a. Advantageously, a flexible, light finger Bl, may be arranged to be rotated by the arm a certain stage of such rotation, preferably four or five hours after the maximum travel of the carriage, serving to bring the finger 81 into contact with the escapement wheel 15a, thus stopping the clock movement. Finger 8'! may have an integral body-portion I00 having a slot "II at an edge thereof, such slot cooperating with a struck-up pin H12 in arm 86 to position the finger 81 and make it movable by the arm 85. The body-portion I00 may additionally serve as a bearing washer for nut 9|.

At the commencement of rewinding the springmotor 62, the clockwise rotation of the drum 63 serves to rotate the arm 86 counter-clockwise of Fig. 8, to a point where its tongue 95 again contacts the side of follower 84. Such movement of the arm 86 frees the escapement wheel E50, of contact with the finger 81, and permits the escapement again to function in normal manner. Continued winding of the spring-motor, as previously stated, returns the entire carriage into position for the commencement of a new time run.

As previously stated, cover 25 is desirably removably secured to base 20. Accordingly, such securement may be effected by .a pinand bay onet-slot organization Hi3, i E34, see 1. It is of particular desirability that the cover of a recording thermometer of the type illustrated be made removable, as under certain conditions of operation the heat capacity of the cover may slow the response of the primary element to temperature change.

Although it is considered preferable to employ spring-motor 02 in connection with the escapement means, it will be understood that carriage drive motor 118, acting as it does to enforce rotation of the drum 63 may, if desired, be the sole motive power. In such circumstance, rotation of drum 63 would be equally under control of the escapement "i5. With such an arrangement escapement stop Bl may be eliminated, as upon completion of maximum carriage travel, motor 18 could induce no further rotation of drum 63.

Desirably, the recorder is entirely of metallic construction, except, of course, for the chart and the chart window. The choice of materials is necessarily influenced by the function of the respective parts; stainless steels and non-ferrous alloys are of particular value in eliminating the possibility of rusting or corrosion in normal use.

Whereas we have described our invention by reference to specific forms thereof, it will be understood that many changes and modifications may be made without departing from the spirit of the invention.

We claim:

1. In a recordin instrument having a chart, a carriage movable relatively to said chart, a primary element mounted on said carriage, and a stylus operatively associated with said primary element .and arranged to inscribe said chart, the combination with means associated with said carriage for raising said stylus from said chart upon a movement of said carriage in one direction, means for moving said carriage with respect to said chart, means for limiting the amount of carriage movement and timing means for controlling the rate of such carriage movement, of means for stopping further action of said timing means at a predetermined time after the completion of allowed movement of the carriage.

2. In a recording instrument as set forth in claim 1, a pivotally mounted arm supporting the said idler, said arm being held against independent rotation in one direction but arranged to rotate in a second direction, spring means acting on said arm in opposition to the carriage drive means during the stage of timed carriage travel, and urging said arm in the direction of its permitted rotation, and means associated with said externalconditions, and chart marking means associated therewith and movable thereby with respect to said chart, the combination with a carriage slidably mounted in said frame for movement in the plane of the chart and drive means for moving said carriage in one direction at a timed rate of speed, of a superstructure pivotally mounted upon said carriage for movement of the marking means toward or away from the plane of the chart, said superstructure having said sensitive element supported thereon, and means associated with said carriage for moving said pivoted superstructure to bring said marking means out of chart marking position upon a movement of said carriage in a direction other than the direction of timed movement thereof and to maintain a said non-marking position regardless of the extent of such carriage movement.

4. In a recording instrument having a frame adapted to carry a chart, an element sensitive to external conditions, and chart marking meansassociated therewith and movable thereby with respect to said chart, the combination with a carria-ge slidably mounted in said frame for movement in the plane of the chart and drive means for moving said carriage in one direction at a time rate or" speed, of a superstructure pivotally mounted upon said carriage for movement of the marking means toward or away from the plane of the chart, said superstructure having said sensitive element supported thereon, and means associated with said carriage drive means for reversing the movement of said carriage at any point intermediate the range of timed travel thereof while canting said sensitive element and said marking means with respect to said carriage.

5. In a recording instrument having a frame adapted to carry a chart, an element sensitive to external conditions, and a stylus associated with. said sensitive element and movable thereby with respect to said chart, the combination of a carriage slidably mounted in said frame and movable in the plane of the chart, drive means for moving said carriage in one direction at a timed rate of speed, a superstructure pivotally mounted upon said carriage for movement of the marking means toward or away from the plane of the chart, said superstructure having said sensitive element fixed thereon, means acting in opposition to said carriage drive means to move said carriage in a direction other than the timed direction thereof, and means operatively associated with said carriage and said superstructure for swinging said stylus out of operative engagement with said chart during said nontimed movement of said carriage and maintaining such non-operative stylus position during said carriage movement.

6. In a recording instrument having a frame adapted to carry a chart, a carriage slidably mounted on said frame and movable in a plua primary element and a chart-marking stylus operatively associated therewith and movable thereby, the combination of a superstructure pivotally mounted upon said carriage and supporting said primary element and said stylus,

and cam means operatively associated with said pivotally mounted superstructure operative on movement of said carriage during its timed movement to maintain said stylus in chart-marking position, and operative upon movement of said carriage in a direction of movement other than its timed direction of movement to move said stylus out of chart-marking position and maintain said stylus in said position during the extent of said last-mentioned carriage movement.

7. In a recording instrument, the combination with a carriage slidably mounted for movement in a plurality of directions, of a structure mounted on said carriage and means for displacing said structure with respect to said carriage, said means including a pin operatively associated with said carriage, said pin having a limited freedom of action with respect to said carriage, and a cam associated with said structure and arranged for operative engagement with said pin, said cam and said pin operating on movement of said carriage to move said structure with respect to said carriage according to the direction of movement of said carriage.

8. In a recording instrument, the combination with a carriage mounted on guideways and movable thereon in a plurality of directions, of a primary-element supporting superstructure rotatably mounted on said carriage and means for rotating said superstructure with respect to said carriage in a direction determined by the movement of said carriage, said means including a cam-engaging pin slidably mounted on said guideways and cam means associated with said superstructure and disposed in operative engagement with said pin.

9. In a recording instrument, the combination with a carriage mounted on guideways and movable thereon in a plurality of directions, of a structure rotatably mounted on said carriage, a cam frame slidably mounted on said guideways and operatively associated with said carriage, a, pin secured to said cam frame, and a cam plate operatively associated with said structure and provided with a cam slot disposed in operative engagement with said pin, whereby upon movement of said carriage with respect to said cam frame said rotatable structure is displaced with respect to said carriage.

10. In a recording instrument, the combination with a carriage mounted on guideways and movable thereon in a plurality of directions, of a structure rotatably mounted on said carriage, a cam frame slidably mounted on said guideways and operatively associated with said carriage, means for restraining free movement of said cam frame, a pin secured to said cam frame, and a cam plate operatively associated with said structure and provided with a cam slot disposed in operative engagement with said pin, whereby upon movement of said carriage with respect to said cam frame said rotatable structure is dis placed with respect to said carriage.

11. In a recording instrument, the combination with a carriage mounted on guideways and movable thereon in a plurality of directions, of a structure rotatably mounted on said carriage, a cam frame slidably mounted on said guideways and operatively associated with said carriage, friction means interposed between said cam frame and said guideways for restraining free movement of said cam frame, a pin secured to said cam frame, and a cam plate operatively associated with said structure and provided with a cam slot disposed in operative engagement with said pin, whereby upon movement of said carriage with respect to said cam frame said rotatable structure is displaced with respect to said carriage.

12. In a recording instrument, the combina tion with a chart, a carriage movable with respect to said chart, chart-marking means pivotally mounted upon said carriage and arranged for movement, into or out of chart-marking position, of drive means for said carriage, clock escapement means operatively associated with said drive means for effecting the movement of said carriage with respect to said chart at a timed rate, means associated with said carriage drive means for reversing the movement of said carriage, means associated with said carriage drive means for moving said chart-marking means out of chart-marking position upon a reversal in the direction of movement of the carriage, and means associated with said carriage-movement reversal means for stopping the operation of said clock escapement.

13. In a recording instrument having a chart, a carriage movable within fixed limits relatively to said chart, a primary element pivotally mounted on said carriage, and a chart-marking stylus operatively associated with said primary element and arranged to be moved into or out of chartmarking position according to the direction of movement of said carriage with respect to said chart, the combination with means for moving said carriage at a predetermined rate of speed with respect to said chart, said means including a clock escapement having a cable drum rotatable thereby at a fixed rate, a drive cable fixed to said cable drum and secured to said carriage, and a motor operatively associated with said carriage and urging said carriage in its timed direction of movement, of means associated with said drive cable to move the carriage in a direction the reverse of the direction of timed movement thereof, and means associated with said lastmentioned means for halting the operation of said clock escapement after the attainment of a predetermined extent of movement of said carriage in the direction of its timed movement.

14. In a recording instrument having a chart, a carriage movable within fixed limits relatively to said chart, a primary element pivotally mounted on said carriage and a chart-marking stylus operatively associated with said primary element and arranged to he moved into or out of chart-marking position according to the direction of movment of said carriage with respect to said chart, the combination with means for moving said carriage at a predetermined rate of speed with respect to said chart, said means including a clock escapement having a cable drum rotatable thereby at a fixed rate, a drive cable fixed to said cable drum and secured to said carriage, and a motor operatively associated with said carriage and urging said carriage in its timed direction of movement, said carriage movement being effected by the paying off of cable from said cable drum, of means associated with said drive cable to move the carriage in a direction the reverse of the direction of timed movement thereof, and means associated with said last-mentioned means for halting the rotation of the said drum subsequently to the limit of movement of said carriage in its timed direction but before the complete unwinding of the cable from said drum.

15. In a recording instrument having a chart and a carriage movable toward or away from said chart within a fixed limit of travel, the combination with carriage drive means and means acting in opposition thereto to control the rate of movement of said carriage in one of its permitted directions, said control means including a clock escapement having" a cable drum operatively associated. therewith and rotating at a timed rate, a cablesecured at one end to said drum and wound thereon and secured to said 10 movable carriage and displaceably mounted idler means for said cable disposed intermediate said drum and said carriage, of means operable to displace said idler means to take up slack in said cable upon the attainment of said maximum 15 permitted travel of 'said carriage in its timed direction of travel.

16. In a recording instrument having a chart and a carriage movable toward or away from said chart within a fixed limit of travel, the combina- 20 tion with carriage drive means and means acting in opposition thereto to control the rate of movement of said carriage in one of its permitted directions, said control means including a clock escapement having a cable drum operatively associated therewith and rotating at a timed "rate, a cable secured at one end to said drum and travel of said carriage in its timed direction of I travel, and means associated with said idler mounting and in operative association with said escapement to halt said escapement and thereupon to halt rotation of said drum at a predetermined time after the attainment of the maximum timed travel of said carriage.

WILLIAM K. MATHESON. ARTHUR C. HOMEYER. 

